ContentRoot, WebRoot, BaseDirectory, and CurrentDirectory

README.md

Assuming you use template defaults

public static void Main()
{
  var host = new WebHostBuilder()
                .UseContentRoot(Directory.GetCurrentDirectory())
                .Build();
}

public Startup(IHostingEnvironment env)
{
     var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                .AddJsonFile("appsettings.json");
}

During development

- Source/                    <=== Directory.GetCurrentDirectory(), IHostingEnvironment.ContentRootPath
  - MyApp.csproj
  - appsettings.json
  + wwwroot/                 <=== IHostingEnvironment.WebRootPath
  - bin/
    - Debug/
      + netcoreapp2.0/       <=== AppContext.BaseDirectory

After publish

Shell location: $ cd publishDir/

- publishDir/                <=== Directory.GetCurrentDirectory(), IHostingEnvironment.ContentRootPath. AppContext.BaseDirectory
  - MyApp.dll
  - appsettings.json
  + wwwroot/                 <=== IHostingEnvironment.WebRootPath

Why?

During development, you don't need to copy wwwroot to bin/Debug/netcoreapp2.0.

During development, you can change *.js files without needing to restart the server.

After publish, all content unifies to the same directory.

Caveat

This requires launching dotnet MyApp.dll from the correct directory.